Some Electron apps cannot access the network

[anna328p]

Describe the bug
Some Electron apps that I attempt to run are unable to access the network. This includes Discord, Google Play Music Desktop Player.

If started in the terminal, Discord repeatedly shows the following error:

[WebContents] did-fail-load -2 ERR_FAILED retry in 1000 ms
[WebContents] retrying load https://ptb.discordapp.com/app?_=1595990016446

GPMDP shows no errors, but refuses to load.

Element Desktop still works.

To Reproduce
Steps to reproduce the behavior:

1. Install Discord
2. Attempt to start Discord
3. Observe the infinite spinner as it attempts to make HTTP requests

Expected behavior

The app is able to access the internet and launches properly.

Screenshots

Additional context

This happened soon after a routine rebuild.

Notify maintainers

Metadata

• system: "x86_64-linux"
• host os: Linux 5.7.10, NixOS, 20.09pre236138.970b2b853d4 (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(root): "nixos-20.09pre236138.970b2b853d4, home-manager"
• channels(anna): ""
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

[anna328p]

It's not just electron. No Steam browser pages load either.

[anna328p]

Duplicate of #93955